New Treatment Approved for Influenza

The Food and Drug Administration (FDA) has approved Xofluza (baloxavir marboxil) for the treatment of acute uncomplicated influenza in patients aged ≥12 years old who have been symptomatic for no more than 48 hours.

Xofluza is a first-in-class, single-dose oral medicine with a novel mechanism of action designed to target influenza A and B viruses, including oseltamivir-resistant strains and avian strains (H7N9, H5N1). Unique to the treatment is its ability to inhibit the cap-dependent endonuclease protein within the flu virus, which is needed for viral replication. “This is the first new antiviral flu treatment with a novel mechanism of action approved by the FDA in nearly 20 years,” said FDA Commissioner Scott Gottlieb, MD.

The approval was based on 2 randomized controlled trials (N=1832) where study patients were assigned to receive Xofluza, placebo, or oseltamivir within 48 hours of experiencing flu symptoms. The data showed patients who received Xofluza had a shorter time to symptom relief vs patients who received placebo. In the CAPSTONE-1 study, no difference was observed between Xofluza and oseltamivir in the time to alleviation of symptoms. The most common adverse reactions associated with therapy included diarrhea and bronchitis.

According to Genentech, the product is expected to be available in the coming weeks. Xofluza will be supplied as 20mg and 40mg tablets.